For several years now, my good friend Michael Wilbur has done an outstanding job of educating the readers of this magazine on the topic of emergency vehicle driving. Obviously, one of the most basic tenets of effective fireground operations is to actually make it to the scene … in one piece...
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Apparatus driver/operators must also be alert for areas that may contain vaulted surfaces. Vaults beneath the ground may be created by underground parking structures, utility chases, drainage culverts, basements that extend under sidewalks or underground transportation systems. These surfaces are unstable for the support of aerial apparatus. Through pre-incident planning, the driver/operator must be familiar with locations where the deployed stabilizer could possibly punch through the surface and cause the aerial apparatus to tip over.
When soft or otherwise unstable surfaces are present or even suspected, avoid the area if at all possible. If it is not possible to avoid the area, the apparatus stabilizers should be properly supported with stabilizer pads and supplemental materials. When possible, park the apparatus in a manner that will allow the aerial device to be operated directly over the front or rear of the apparatus. This lessens the possibility of a stabilizer settling into the surface. It also lessens the chance of the apparatus tipping over even if it does settle into the surface.
Weather conditions can affect the spotting of an aerial apparatus in several ways. These include cold, hot or windy weather conditions. Driver/operators must have an understanding of how to deal with the weather extremes that are common to their jurisdiction.
Photo by Michael A. Wieder
Always place the stabilizer pads beneath the stabilizer boot, regardless of the surface type.
The most common spotting consideration that faces driver/operators in cold weather conditions is the presence of ice or snow on the parking surface. When possible, the driver/operator should avoid parking the apparatus and deploying the aerial device on snowy or icy roads. However, since this is not always possible, the driver/operator must know how to make the operation as safe as possible. The driver/operator should monitor icy ground for melting conditions that could decrease stabilizer stability. In some cases, after the stabilizer has been lowered onto an icy or snow-packed surface, the ice/snow may melt or break away leaving the stabilizer off the ground. This will require the stabilizer to be lowered further to ensure solid contact with the ground.
Icing of ladders, booms and platforms requires additional caution during operation due to the weight of the ice. The amount of weight added to the aerial device by firefighters and equipment has to be decreased when icing conditions are present. Try to avoid parking the apparatus in a position where the raised aerial device will be subject to accidental contact with fire streams or overspray. If the aerial device is going to be used for elevated master stream operations, avoid parking it so that the stream will be operated against the wind. This will minimize overspray reaching the aerial device. If the aerial device does receive a buildup of ice, it may be necessary to spray it with a de-icing fluid so that normal operation may be resumed.
The primary spotting consideration associated with hot weather is that extreme heat may tend to weaken marginal or otherwise firm paved surfaces. For example, an asphalt parking lot that may provide a marginal level of support during more temperate weather conditions will become soft during periods of extreme heat. This may result in an unstable base.
Moderate to high winds impose a dynamic load on the aerial device and may reduce the overall stability. This is caused by the force of the wind blowing against the device and trying to move it in a direction for which it was not designed. The movement by the wind also magnifies the other loads placed on the ladder by personnel and equipment. When it is necessary to operate during high wind conditions, spot the apparatus in a manner that requires the aerial device to be raised only to the minimum extension needed. It is also helpful to position the apparatus so that the aerial device may be used over the front or rear of the vehicle, parallel to the wind. Driver/operators and company officers should also be aware of locations in the response district and sides of certain buildings that are more prone to gusting wind conditions and avoid them when possible. Always adhere to the manufacturer's recommendations for operations in windy conditions.
Electrical Hazards & Ground Or Overhead Obstructions